posterior ischemic optic neuropathy following percutaneous nephrolithotomy

purpose: to report a case of posterior ischemic optic neuropathy (pion) following percutaneous nephrolithotomy (pcnl). patient and findings: a 57-year-old male who underwent pcnl because of renal stone was referred due to painless bilateral visual loss to the level of light perception immediately after the operation. the patient had history of diabetes mellitus, hyperlipidemia, and mild anemia. ophthalmic examinations were unremarkable and optic discs were pink and without any sign of swelling. visual fields were severely affected, but neuro-imaging was normal. within three months, visual acuity and visual fields improved dramatically and optic discs became mildly pale. the clinical course was typical for pion. conclusion: pion is a rare cause of severe visual loss following surgery. severe blood loss, hypotension, anemia, and position of the patient during surgery are the most important risk factors. this is the first report of pion following pcnl. urologists, ophthalmologists and anesthesiologist should be aware of this entity, and rare possibility should be discussed with the patient before surgery. preventive measures against pion should also be taken.